The manufacture of alcohols, particularly of fatty alcohols, is of great industrial significance.
The catalytic hydrogenolysis of carboxylic esters is an attractive manner of manufacturing these alcohols; however it has been limited up to now by the poor performances of the known catalysts:
the catalysts comprising mixed copper and chromium oxides, with or without additives, require working under high pressure, in nearly all cases above 200 atmospheres, and at a temperature of 250.degree. to 350.degree. C., PA1 the catalysts comprising supported transition metals are required to operate at a temperature lower than 250.degree. C. and preferably lower than 200.degree. C., to limit the degradation of the resultant alcohol to hydrocarbons, which requires operating pressures above 100 bars to obtain good selectivities at an acceptable conversion level.
Catalyst comprising rhodium and tin or lead on silica are disclosed in Chemical Abstracts, vol. 93, Nov. 25, Dec. 22, 1980, page 761, No. 238,371 s; lead and silica were supplied in ionic form.
U.S. Pat. No. 3,825,503 discloses a rhodium-tin catalyst obtained from water-soluble soluble metal salts.
DE No. 3 019 582 discloses a method for manufacturing catalysts comprising both noble and non-noble metals; water-soluble metal salts are used.